Three Presidential addresses, delivered recently in this country and abroad, give admirable surveys of the present status, of past growth and of the future needs of chemistry. The address of Professor F. W. Clarke to the American Chemical Society, given December 30, 1901, on 'The Development of Chemistry' deals with the four principal agencies that have been instrumental in building the chemical structure of to-day; these are: private enterprise, the commercial demand, governmental requirements, and university teaching. At the beginning all these agencies had not been established, the two great stimuli to chemical research were the intellectual interest of the problem to be solved, and practical utility; these still have great influence, but the most important need at the present time, says Professor Clarke, is a well equipped and endowed research laboratory, in which to conduct systematic and thorough investigations.

Dr. Ira Remsen chose for his address to the same society, given a year later, 'The Life History of a Doctrine.' In a scholarly and witty way he sketched the early history, development and modern phases of the atomic theory, saying that in the light of late advances we must enlarge our conception of atoms. He pointed out that the many obituaries on the electrochemical theory of Berzelius were probably premature, since in the latest conception of atoms electrical charges play an important part. An atom charged with electricity is called an ion, and only then is it ready for action. At the same time President Remsen refers to physicists the explanation of some of the features of the theory of ions.

Professor James Dewar, in his address as president of the British Association for the Advancement of Science, delivered September 10, 1902, was of a more comprehensive nature, reviewing many aspects of science. Incidentally he compared the chemical equipments of England and Germany to the decided disadvantage of the former, stating that Germany possessed a professional staff one third larger in numbers and superior in quality. One firm in Germany, employing 5,000 workmen, has a staff of 160 chemists, 260 mechanics and engineers, besides 680 clerks. Owing to the high education and practical character of their chemists German manufacturers enjoy a monopoly. Passing from this theme, Professor Dewar gave some of the interesting results obtained in his researches on low temperatures, especially in liquefying hydrogen and helium. The whole address, which is very readable, can be found in the October numbers of Science. Besides these addresses another one by Dewar must not be overlooked, the 'Centenary Commemoration Lecture' at the Royal Institution.

The Bi-Centennial of Yale University, celebrated in 1901, was appropriately marked by the publication of several superb volumes containing chemical research conducted by professors and instructors in that institution. Two of these are from the Kent Chemical Laboratory, and embody the labors of Professor F. A. Gooch, and of some of his assistants; the other two are from the Sheffield Scientific School, and contain chiefly the labors of Professor Horace L. Wells. The ​papers are limited to the ten years preceding their publication and reflect great credit on their authors. To attempt any synopsis of the contents of these volumes would lead to technical details beyond the scope of these columns.

Text-books in English and in other languages continue to flow from the press in undiminished numbers; some are very elementary, giving no novelty in treatment nor other advantages over the host of those preceding them, but others are on a higher plane, endeavoring to embody the most recent theories and to adapt them for the purposes of instruction. One of the most praiseworthy of the latter group first appeared in Holland in 1898, was soon translated into German, and two years later into English. Its author is Dr. A. F. Holleman, professor at the University of Groningen, its translator is Dr. Harmon C. Cooper, of Syracuse University, and it bears the imprint of John Wiley and Sons, New York City. Holleman's text-book combines the new achievements of physical chemistry with the mass of long-established facts of inorganic chemistry so as to form a unified whole; it makes it unnecessary for beginners to get acquainted with the common phenomena of elementary chemistry by the study of one book written on the old plan, and then to take up the independent study of those laws of physical chemistry established by Ostwald, van't Hoff, Arrhenius, and their disciples, as set forth in some other manual devoted to those subjects. All these features are combined by Holleman in a single graded course, making it a superior, up-todate work. The translation by Dr. Cooper is satisfactory and free from ambiguity.

Another book of very high grade is that by Dr. Mellor, of Manchester, England, entitled: 'Higher Mathematics for Students of Chemistry and Physics.' Chemistry is developing along mathematical lines, and it is evident that its students must hereafter be practical mathematicians. Of several books applying mathematics to the scientific evolution of chemistry, Mellor's book is very complete and satisfactory, and can be warmly recommended.